Engines, including diesel engines, gasoline engines, gaseous fuel powered engines, and other engines known in the art ignite an air/fuel mixture to produce heat. Fuel directed into a combustion chamber of the engine can be ignited by way of a spark plug, a glow plug, or an AC/DC ignition source. The heat and expanding gases resulting from this combustion process are directed to displace a piston or move a turbine blade, both of which can be connected to a crankshaft of the engine. As the piston is displaced or the turbine blade is moved, the crankshaft is caused to rotate. This rotation is utilized to drive a device such as a transmission or a generator to propel a vehicle or to produce electrical power.
It has been established that a well-distributed flame inside the combustion chamber of an engine promotes improved combustion of the air-fuel mixture. Improved combustion can result in a reduction in air pollution and fuel consumption. One way to produce a well-distributed combustion flame is through the use of a combustion or ignition prechamber (referred to herein as “prechamber”). The prechamber can form a portion of the engine. For example, the prechamber may be formed within a high-temperature prechamber housing associated with a cylinder head, which is configured to close off one or more cylinders of an engine block. The high temperature prechamber housing may be connected to the cylinder head by a body assembly that includes one or more passages for directing fuel and air into the prechamber before the air-fuel mixture is introduced into the cylinder associated with the prechamber. The prechamber assembly may be positioned at least partially within an ignition bore in the cylinder head, and ignition of an air-fuel mixture may occur within the prechamber. Ignition of the air-fuel mixture within the prechamber may be initiated with a spark plug or by pressurizing the mixture within the prechamber until auto-ignition occurs. Flame propagation is then transferred to the combustion chamber by way of orifices in the prechamber housing, enabling complete ignition of a lean fuel-air mixture within the cylinder.
While the use of a prechamber provides certain performance improvements, the prechamber housing also requires periodic replacement or remanufacture, as even the high temperature materials forming the prechamber housing may eventually wear, corrode, or otherwise deteriorate to a level that may affect performance of the engine. Deterioration of the prechamber housing or openings from the prechamber housing into the cylinder can also affect flame propagation to the cylinder, and thereby affect the emission levels for the engine.
One attempt at improving heat removal from a prechamber device in order to improve the life of the prechamber device is disclosed in U.S. Pat. No. 9,217,360 (the '360 patent) that issued to Pierz on Dec. 22, 2015. In particular, the '360 patent discloses a prechamber device that includes a shell with an interior portion and an exterior portion and a thermally conductive core portion positioned within a cavity formed between the interior and exterior portions, and coolant flow passages providing liquid coolant to the exterior portion of the prechamber device.
Although the prechamber device of the '360 patent may have improved life, the complex structure and need to prevent the liquid coolant from flowing into contact with the combustion igniter may increase costs and reduce manufacturability. Moreover, the '360 patent does not address the problems associated with disassembly of the prechamber housing, or remanufacture and replacement of one or more components of a prechamber assembly.
The disclosed prechamber assembly and method of remanufacturing a prechamber assembly are directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.